1.2.4 Audio + Visual Formats And Compression

Question 1

What are images saved electronically made up of?

Answer 1

Series of pixels

Question 2

What generates detail?

Answer 2

Changing colour or brightness of each pixel

Question 3

How can images be converted into binary?

Answer 3

Binary code to represent each pixel

Question 4

How many colours does a 1-bit image have?

Answer 4

Two
0 or 1

Question 5

How many colours does a 2-bit image have?

Answer 5

Four colours
00, 01, 10, 11

Question 6

How can more colours be added?

Answer 6

Longer binary codes

Question 7

What is colour depth?

Answer 7

Number of bits per pixel

Question 8

How many colours does a 4-bit image have?

Answer 8

16

Question 9

What colour depth do modern devices use?

Answer 9

24-bit
16,777,216 colours

Question 10

What makes higher resolution?

Answer 10

More pixels

Question 11

How is an image file size determined?

Answer 11

Size in pixels
Colour depth

Question 12

What does metadata include?

Answer 12

Technical data generated by camera = image properties, shutter speed, resolution, GPS location, date and time
Data added manually buy the user = places, names or captions, comments or people’s names or copyright information

Question 13

What is metadata?

Answer 13

Information stored within the same file

Question 14

How is live sound recorded?

Answer 14

Microphone

Question 15

What is live sound called?

Answer 15

Analogue sound

Question 16

What is Sampling

Answer 16

To store sound on a computer, it must be converted to digital file and stored as binary

Question 17

Sample rate

Answer 17

Number of samples taken each second

Question 18

What happens if the sample rate increases?

Answer 18

Quality of sound file does

Question 19

Bit depth

Answer 19

Number of bits used to encode the sample

Question 20

What is recording duration measured in?

Answer 20

Seconds

Question 21

Data compression

Answer 21

Used to reduce large files

Question 22

What are the benefits of data compression?

Answer 22

Storage space required on mobile devices and home computers can be reduced
Smaller files can be uploaded and downloaded more quickly
Limits placed on file sizes by streaming and email services can be avoided

Question 23

What is lossy compression?

Answer 23

Removes data (duplicated elements) to create a smaller file size.

Question 24

What happens to data removed during compression?

Answer 24

Removed permanently

Question 25

What are file types for lossy compression?

Answer 25

JPEG, MP3, MP4, and GIF

Question 26

What is lossless compression?

Answer 26

Uses software algorithms to compress data but then reconstructs it to its original form, preserving original file

Question 27

What are the file types of lossless compression?

Answer 27

RAW, WAV, TIFF, BMP

Question 28

How do you calculate text file?

Answer 28

Bits per character x number of characters

Question 29

How do you calculate sound file?

Answer 29

Duration (s) x samples rate x bit depth

Question 30

How do you calculate image file size?

Answer 30

Image height x width (pixels) x colour depth